The present invention relates to a safety enhanced motorcycle helmet. Helmets that are currently employed by drivers of motorcycles, and in other similar environments of use do not effectively absorb impact forces, nor do they properly decelerate and spread blows from the point of impact.
For some motorcycle helmets it has been found that motorcycle helmet foam liners are too stiff and hard and produce distortion or inbending of the head when an impact force is applied to the helmet. Their post-crash analysis and evaluation of helmets that have been in crashes involving impacts to the helmets revealed very little crushing of the foam liner of the helmet indicating that the density of the foam ought to be reduced.
In a study it was found that the human head deforms elastically on impact, and significant elastic deformation of the head can result in brain damage. Thus, it would be preferred to have a softer liner material in the helmet so that less deformation of the head occurs. As is known, that distortions of the human head beyond 1 to 2 mm can cause intracranial damage.
In a typical motorcycle helmet, the thickness of the shell of the helmet in the temple area of the user's head is about 4 mm, whereas the thickness of the foam liner is in the range of 12 to 30 mm. As is well known, the temporal area of the human skull is a zone of weakness. Bone tests have indicated that bone in the temporal region of the human head has only ½ to ⅓ the strength as compared to other areas of the human skull. Since a significant number of impacts occur in the temporal region, it is imperative that motorcycle helmets be designed to account for this fact.
In another study it was found that it would not be appropriate to design a motorcycle helmet employing a foam layer entirely of low density foam. Such a helmet liner would be too soft and resilient, would cause the helmet to move with respect to the user in an undesirable fashion, and it would also not be sufficiently durable to provide a reasonable useful life for the helmet.
The manufacturers of motorcycle helmet are constantly trying to improve the motorcycle helmet as more accident or material information becomes available. In this regards several manufacturers have address this issue in a variety of ways.
U.S. Pat. No. 4,586,200 (Melvyn C. Poon), the entire disclosure of which is incorporated herein by reference, discloses a protective crash helmet designed to increase the safety and comfort of a motorcycle rider is described. One of the protective layers inside the helmet includes inflatable air bubbles whose pressure and consequently size may vary when connected to an outside air pressure supply. This unique feature allows a more precise fit to a rider's head, all of which are not the same shape. In addition, the protective crash helmet also has a ventilating system for cooling the interior of the crash helmet. An air inlet located on the front of the helmet with a valving door, allows air inside the helmet whereby the passageway is the space between the respective air bubbles. The air outlet located in the rear of the helmet allows the air to pass through the helmet thereby cooling the rider.
U.S. Pat. No. 5,148,950 (Dave K. Hosaka), the entire disclosure of which is incorporated herein by reference, discloses embodiments of a helmet structure includes a separably movable fluid pouch mounted within the helmet below the forward helmet shell opening, including an “L” shaped conduit directed upwardly and mounted medially to a respective right and left fluid cavity of the reservoir structure. The organization utilizes hook and loop fastener tabs mounted to a forward surface of the right and left reservoirs for mounting to an interior fibrous surface of the helmet shell. A modification of the invention includes a storage tank mounted to the handle bar structure of an associated motorcycle or bicycle construction utilizing a storage tank conduit hose in communication with a valve mounted to the storage tank to direct fluid to the right and left reservoir pouches.
U.S. Pat. No. 5,669,079 (Don E. Morgan), the entire disclosure of which is incorporated herein by reference, discloses embodiments of a safety enhanced motorcycle helmet provide enhanced cushioning to protect sensitive areas of the user's head. In each embodiment, a high density foam material is provided just under the thick outer shell of the helmet. The various embodiments contemplate embedding of various designs of low density foam materials within the high density foam layer. Embodiments include strips of low density foam, low density cylindrical foam plugs, channels formed within the high density foam layer and containing low density foam balls, and low density foam wedge plugs.
U.S. Pat. No. 6,865,759 (Tony M. Pearce), the entire disclosure of which is incorporated herein by reference, discloses cushions and cushion elements with non-intersecting-columnar elastomeric members exhibiting compression instability are disclosed. The cushions and cushion elements may be made from gelatinous elastomer materials. The cushions and cushion elements have application in a variety of fields, including foot care products, seat cushions, mattresses and mattress overlays for consumer and medical applications, carry straps, sports injury prevention, orthopedics, vibration dampeners for electrical and electronic equipment, shock absorbers and others.
U.S. Pat. No. 7,140,126 (Laura Crane, et al.), the entire disclosure of which is incorporated herein by reference, discloses a removable insole for insertion into footwear, includes a lower layer made of a viscoelastic gel and including a lower surface, an upper surface, a toe portion, a heel portion and a medial arch portion interconnecting the toe portion and the heel portion, a first recess formed in the lower surface of the toe portion and a second recess formed in the lower surface of the heel portion, each recess having a peripheral side wall and a top wall, a plurality of thin, parallel, spaced apart sinusoidal wave shaped spring walls formed from the viscoelastic gel and connected to the top wall and the peripheral side wall in each recess, and the spring walls having lower edges generally coplanar with a lower surface of the toe portion and heel portion which is in surrounding relation to the respective recess; and a top cover secured to the upper surface of the lower layer.
U.S. Patent Publication No. 20090158506 (Matthew T. Thompson, et al.), the entire disclosure of which is incorporated herein by reference, discloses a helmet includes an outer shell, an energy-absorbing layer disposed inside the outer shell, and a liner disposed inside of the energy-absorbing layer. The liner includes a central portion configured to extend along a longitudinal axis that runs between a front portion of the helmet and a rear portion of the helmet, a first side portion releasably coupled to the central portion, and a second side portion releasably coupled to the central portion.
Therefore, there is a need for improvement in the field of motorcycle helmets, and in particular in the field of helmet safety liners.
This invention improves on the deficiencies of the prior art and provides an inventive liquid-gel impact reaction liner for a motorcycle helmet.